We think of it in terms of applying rules and laws - alternatively in applying principles. We look for precedents, and try to treat similar cases identically.
Yet, a just and loving father Father treats each child differently by sex, age, character, intelligence. Typically, the superficially similar cases are actually significantly different and require different responses.
All rules, laws, principles and the like are partial and distorted summaries of justice - and ideal justice is best captured by the loving Father metaphor; which is also the best metaphor for God.
Yet it is striking how often we judge God by His conformity to those partial and distorted summaries of rules, laws and principles which would not even suffice for an earthly Father! - and in situations in which the primary Fatherly metaphor reveal justice to be clear and obvious!
It is close to the essence of Christianity that each person is unique and that each is the child of God our loving Father - therefore, with each 'case' unique, justice cannot be captured by generalities and precedents.
In an abstract sense, there are no precedents to 'family justice' yet that justice is understandable and principled and indeed the model of all other forms of justice; how much more will this be the situation for divine justice!